Hepatitis A virus (HAV) has only recently been propagated in cell cultures and is very difficult to isolate. There are no more than six or eight strains yet isolated, and most of them require passage through another species or in cell lines that are not suitable for vaccine development. Since HAV cannot be produced in large quantities from tissue culture cells, the development of in vitro culture systems depended upon the development of the HAV-specific detection system by immunofluorescence (IF).
At the present time, marmosets are the major source for production of hepatitis A virus (HAV) and hepatitis A antigen (HA Ag). However, the decreasing availability of these animals and the high cost of acquiring and maintaining them necessitates an alternative source of antigen for serologic testing. This invention describes the HM-175 strain of HAV suitable for the production of tissue culture-grown HA Ag as an antigen for radioimmunoassay of anti-HAV.
The isolation of HAV directly from clinical specimens into a cell line for vaccine production (primary AGMK) suggests that additional in vitro cultivation of the virus will yield a strain suitable for vaccine development.
The HM-175 strain of hepatitis A virus has been stored at the Building 7 depository of the National Institutes of Health, a recognized cold depository. The dates of storage for the first five serial passages of the virus are listed below:
______________________________________ Passage Level Date of Storage ______________________________________ 1 December 18, 1979 2 February 19, 1980 3 March 21, 1980 4 April 24, 1980 5 May 22, 1980 ______________________________________